1. Field of the Invention
The present invention relates to a gas turbine combustor and an operating method thereof.
2. Description of Prior Art
The present invention specifically relates to a low NOx type gas turbine combustor which emits low levels of nitrogen oxides. The prior art has been disclosed in Japanese Application Patent Laid-Open Publication No. Hei 05-172331.
In a gas turbine combustor, since the turndown ratio from startup to the rated load condition is large, a diffusion combustion system which directly injects fuel into a combustion chamber has been widely employed so as to ensure combustion stability has been made available.
In said prior art technology, a diffusion combustion system has a problem of high level NOx. A premixed combustion system also has problems of combustion stability, such as flash back, and partial loading operation. In actual operation, it is preferable to simultaneously solve those problems.